This summer cleanup was completed at the three-acre site
known as the Ash Pit, located in the southeastern part of the Laboratory. The
Ash Pit cleanup called for the removal of some trees, backfilling of soil to
even out the grade, the placement of 12-inches of top soil to cover the ash, and
finally the reseeding of the area with native grasses.
Trees that were removed at the Ash Pit were taken to an
off site compost facility to be recycled.
|The three-acre Ash Pit is cleared as part of the cleanup|
|Soil cap is applied to the Ash Pit in mid-July|
By late July, holes were dug in
the soil cap to confirm the thickness of soil. Native grasses, including rye and
switch grass, were then sown into the new, clean topsoil layer.
|40 Pounds of Native grass seeds are sown into a newly established topsoil layer at the Ash Pit.|
The Ash Pit was used for
disposal of incinerator ash and slag from a solid waste incinerator that
operated from1943 to 1963. The southern portion was cleared of trees and shrubs,
and had in some areas ash and slag on the surface. The northern portion has a
road and grass-covered fire break.
The principal contamination sources in the Ash Pit were
bottom ash from the incinerator and coal ash. Low concentrations of
radionuclides above site background levels had been detected in this area. These
levels are typical of ash. Other contaminants of concern included metals such as
zinc, lead and copper.
The cleanup work completed this
summer represents the final preferred remedy for the Ash Pit and is consistent
with the Operable Unit I Record of Decision. The remedy specified the placement
of a soil cap, along with institutional controls and monitoring.